A high number of samples can cause a heavy load on the switch CPU. To limit the load, there is a CPU throttling mechanism to protect the switch.
Note
Sflow sampling is limited to 2000 packets per second in the CPU. Any packets sent at a rate greater than 2000 pps are dropped.On a stand-alone switch, whenever the limit is reached, the sample rate value is doubled on the ports from which the maximum number of samples are received. For ports that are sampled less frequently, the sampling rate is not changed; the sub-sampling factor is adjusted downward.